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EP 0 832 183 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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24.08.2005 Bulletin 2005/34 |
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Date of filing: 28.05.1996 |
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International application number: |
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PCT/US1996/007538 |
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International publication number: |
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WO 1996/038534 (05.12.1996 Gazette 1996/53) |
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IMPROVED FAT SPLITTING PROCESS
VERBESSERTES VERFAHREN ZUR FETTSPALTUNG
PROCEDE AMELIORE DE FRACTIONNEMENT DES CORPS GRAS
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Designated Contracting States: |
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BE DE ES FR GB IT NL |
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Priority: |
31.05.1995 US 456209
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Date of publication of application: |
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01.04.1998 Bulletin 1998/14 |
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Proprietor: Cognis IP Management GmbH |
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40589 Düsseldorf (DE) |
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Inventors: |
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- ANDERSON, Kevin, W.
Indian Springs, OH 45011 (US)
- WENZEL, J., Douglas
Cincinnati, OH 45245 (US)
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References cited: :
WO-A-94/23051 US-A- 3 875 007 US-A- 5 273 898
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WO-A-98/27219 US-A- 4 678 580 US-A- 5 470 741
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- "COMBINED ENZYMATIC/NON-ENZYMATIC FAT SPLITTING" RESEARCH DISCLOSURE, no. 336, 1
April 1992 (1992-04-01), page 310 XP000305037 ISSN: 0374-4353
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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1. Field of the Invention
[0001] This invention relates to improvements in the pressure splitting of fats and oils
by means of a presplitting step utilizing lipase hydrolysis wherein the glycerine
evaporator condensate from the pressure splitter is recycled to the presplitter.
2. Background of the Invention
[0002] Fats and oils are also know as triglycerides, which are the reaction products of
glycerine and fatty acids. Fatty acids and glycerine can be produced by reversing
the reaction between glycerine and fatty acids which is known as hydrolysis. Commercially,
the hydrolysis reaction is known as "splitting" in that glycerine and fatty acids
are hydrolyzed or "split" apart to break the bonds between the acid and the glycerine.
[0003] Typically, the fat or oil is split commercially in a pressure splitter wherein preferably
the fat or oil is introduced at one end and water introduced at the opposite end thereof
in a countercurrent flow pattem. In operation, the pressure splitter provides substantial
amounts of heat and pressure to the mixture of triglyceride and water to effect the
hydrolysis. However, because the triglyceride is hydrophobic, the amount of actual
contact between the water phase and the fat phase is relatively low. It is believed
that after a period of time in the splitter individual triglyceride molecules incompletely
hydrolyze, splitting off one acid molecule to create a di-glyceride or two acid molecules
to form a monoglyceride. The mono- and di-glycerides are less hydrophobic than the
starting triglyceride, and mix more thoroughly with water. As a result, the mono-
and di-glycerides function as emulsifiers to improve mixing of the triglyceride with
water. Under the turbulent conditions within the pressure splitter, it is believed
that the mono- and di-glycerides improve the extent of mixing between the triglyceride
and water, thereby facilitating the hydrolysis reaction.
[0004] The period of time during which the hydrolysis rate is depressed is known as the
induction period. During the induction period, heat is input to the pressure splitter
and pressure is generated, but few hydrolysis products are being produced. The volume
of triglycerides hydrolyzed within the pressure splitter would be increased substantially
if the induction period could be eliminated or at least substantially reduced.
[0005] One way of eliminating the induction period is to employ a partial or presplitting
step wherein a lipase with a minor amount of water is combined with the fat or oil
feedstock with agitation prior to pressure splitting. The partial splitting step is
performed during that time while the fat or oil is stored in a holding tank prior
to pressure splitting. The fat or oil is typically held in a heated tank for at least
two days prior to pressure splitting, and partial hydrolysis can be performed within
that period of time with the aid of a lipase catalyst. The lipase is added to the
presplitter as an aqueous solution. Prior to the present invention, the lipase solution
was made by mixing the lipase with fresh water. The lipase solution is agitated at
a rate sufficient to render the solution miscible or finely dispersed in the feedstock.
The agitation is continued for a period of time sufficient to raise the acid value,
and at a temperature optimally just below the deactivation temperature of the lipase.
It has been found that agitation of a tallow feedstock with lipase and water for 24
to 48 hours at temperatures of up to about 60°C can produce acid values in the range
of at least 40 to 80 (mg KOH/g sample). In comparison, complete hydrolysis of tallow
would produce an acid value from the liberated carboxylic acids of 205.
[0006] The international patent application WO 94/23051 discloses a fat splitting process
for the production of carboxylic acids and glycerin, comprising forming a presplitting
mixture by adding glyceride, water and a lipase, whereby the type of water does not
materially affect the reaction.
[0007] The preferred commercial presplitting process is carried out in a continuous manner
as described in copending application serial number US (08/356,047), filed on 12/14/94,
the entire contents. In the continuous process, a triglyceride to be treated, such
as tallow, is introduced continuously into a reaction vessel at an elevated temperature,
e.g. at about 50-60°C. A lipase slurry in water containing from 0.01% to 2%, preferably
0.08% to 1.2% by weight of lipase is simultaneously introduced on a continuous basis
into the reaction vessel. The flow rates of the triglyceride and of the tallow slurry
are adjusted to provide from 2% to 5% by weight of water based on the weight of triglyceride,
and to provide a residence time for the triglyceride in the reaction vessel of from
24 to 96 hours, depending on the temperature and on the activity of the lipase used
in the process. Under these conditions, a steady state acid value in the effluent
ranging from 25 to 100 is obtained, and usually from 50 to 100. The mixture in the
reaction vessel is thoroughly mixed throughout the process, using any agitation or
stirring means that will accomplish such thorough mixing. The effluent presplit triglyceride
is then fed directly to a pressure splitter to complete the reaction and produce fatty
acids and glycerine. Typically, the fat or oil is split commercially in a pressure
splitter wherein preferably the fat or oil is introduced at one end and water introduced
at the opposite end thereof in a countercurrent flow pattern. In operation, the pressure
splitter provides substantial amounts of heat and pressure to the mixture of triglyceride
and water to effect the hydrolysis. Fatty acids produced in the presplitter are removed
by phase separation. The liquid effluent from the pressure splitter, also known as
sweetwater, is sent to a disk centrifuge and then into a series of steam evaporators
wherein the water is separated from the glycerine by evaporation and the evaporated
water is condensed to form the glycerine evaporator condensate. It has been found
that the use of fresh water in the presplitter causes problems downstream. Because
of the presence of calcium and magnesium salts in the fresh water, fatty acid soaps
are formed in the presplitter. The fatty acid component of these soaps is supplied
by the recycled glycerine evaporator condensate. These soaps build up in the disk
centrifuge and the glycerine evaporator condensate bottoms.
[0008] One solution to the downstream problems mentioned above is to use the glycerine evaporator
condensate as the aqueous phase in the presplitter because of the presence of only
minute amounts of calcium and/or magnesium, if any. However, it has been found mixing
the glycerine evaporator condensate, the lipase, and make up fresh water inactivated
the lipase in the presplitter probably due to the low pH of the glycerine evaporator
condensate and the high temperature (160°F).
SUMMARY OF THE INVENTION
[0009] The present invention utilizes the glycerine evaporator condensate from the pressure
splitter as the water phase of the presplitter without the concomitant inactivation
of the enzyme. The surprising discovery has been made that if the glycerine evaporator
condensate from the pressure splitter is added to the presplitter separately from
a lipase-fresh water slurry, the lipase does not undergo inactivation. Thus, the process
according to the invention utilizes the glycerine evaporator condensate thereby minimizing
the effluent emissions from a pressure splitting operation.
[0010] The present invention relates to a continuous process for the production of carboxylic
acids and glycerine from a glyceride. The first step of the process involves the formation
of a presplitting mixture by separately adding the glyceride, an effective lipase
in an amount sufficient to produce partial splitting of the glyceride, and water.
The water used in the formation of the presplitting mixture is water that has been
separated from the glycerin-water effluent stream from the pressure splitter and recycled.
The next step involves the pressure splitting which entails mixing the partially split
glyceride from the presplitter with water and heating under conditions of temperature
and pressure effective to substantially complete the splitting of the glyceride into
component fatty acids and a glycerin-water stream. The temperature in said pressure
splitter is in the range of 200 to 300°C, preferably in the range of 240 to 280°C.
The pressure in said pressure splitter is in the range of 3.10 to 6.55 MPa (450 to
950 psi). The water is then separated from the glycerine-water stream and the water
is recycled to the presplitter.
BRIEF DESCRIPTION OF THE DRAWING
[0011]
Figure 1 is a flow chart of a fat pressure splitting process containing a presplitting
operation wherein the glycerine evaporator condensate from the pressure splitter is
recycled to the presplitter.
Figure 2 is a graph of acid value of the water phase in the presplitter as a function
of time. An aqueous phase from glycerine evaporator condensate which has been completely
neutralized gives the greatest acid value increase indicating that the triglycerides
are being split into fatty acids.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention relates to an improvement in a fat pressure splitting process
having a presplitting step wherein the glycerine evaporator condensate from the pressure
splitter is recycled to the presplitter. The process according to the invention is
depicted in Figure 1. The triglyceride, such as tallow, is introduced continuously
into the presplitter at an elevated temperature less than 70°C, e.g. at 50-60°C. A
slurry containing lipase and an amount of fresh water sufficient to rehydrate the
lipase are introduced into the presplitter vessel along with the triglyceride to be
split. The remainder of the water required for the presplitting operation is introduced
separately, preferably (after or before) the addition of the lipase-fresh water. A
lipase such as the lipase from Humicola lanuginosa, commercially available as Novo
LIPOLASE™ 100T, is simultaneously introduced on a continuous basis into the reaction
vessel. The flow rates of the triglyceride and of the tallow slurry are adjusted to
provide from 2% to 5% by weight of water based on the weight of triglyceride, and
to provide a residence time for the triglyceride in the reaction vessel of from 24
to 96 hours, depending on the temperature and on the activity of the lipase used in
the process. Under these conditions, a steady state acid value in the effluent ranging
from 25 to 100 is obtained, and usually from 50 to 100. The mixture in the reaction
vessel is thoroughly mixed throughout the process, using any agitation or stirring
means that will accomplish such thorough mixing. The fatty acids formed in the presplitter
form a separate liquid phase from the sweetwater phase the principal contents of which
are water, residual triglycerides, and glycerine. The sweetwater effluent from the
pressure splitter is sent to a disk centrifuge to remove the residual triglycerides
and then into a series of steam evaporators wherein the water is separated from the
glycerine by evaporation and the evaporated water is condensed to form the glycerine
evaporator condensate. The glycerine evaporator condensate is recycled to presplitter
and added sequentially with respect to the fresh water-lipase slurry. The glycerine
evaporator condensate can be added either before or after the addition of the fresh
water-lipase slurry. If the glycerine evaporator condensate and fresh water-lipase
slurry are added simultaneously to the presplitter, the lipase will be inactivated.
[0013] The triglycerides which can be used in the process according to the invention include
but are not limited to tallow, lard, coconut oil, canola oil, palm oil, and mixtures
thereof. The preferred lipase is a 1,3-position specific enzyme. This type of lipase
cleaves the ester linkage at the 1 and 3 positions on the triglyceride, but leaves
the remaining ester linkage intact. Preferred lipases include the lipase from Humicola
lanuginosa, commercially available as Novo LIPOLASE™ 100T and the lipase from Burkholderia
cepacia, ATCC 21,808, as described in U.S. patent US (3,875,007) the entire contents.
Other preferred lipases are those from Mucor miehei, Candida cylindracea, or Rhizopus
arrhizus. Combinations of these lipases can also be used.
[0014] The following examples are meant to illustrate but not to limit the invention.
Example 1
DM Tallow Presplitting Using Fresh Water
[0015] A total of 44 million pounds of DM tallow (AV = 7.3) was presplit to an acid value
of 48.4 by feeding DM tallow (30,450 lb/hour) to a continuous presplitting reactor
(2.5 MM lb working volume) equipped with a 10 hp blending agitator. LIPOLASE™ 100T
was rehydrated in a portion of the city water feed and added simultaneously with the
fat and city water fed to the reactor to give a water/tallow feed ratio of 2.36% and
a lipase/tallow feed rate of 74.3 ppm. The presplit tallow effluent was then processed
on a high pressure splitter at feed rates 15%-18% higher than can be achieved using
non-presplit DM tallow. Presplitting by this method caused a canyover of some fatty
acids and unreacted glycerides into the sweetwater, which is normally recovered by
centrifugation for reprocessing, while at normal levels with this presplit raw material,
was not efficiently recovered by the centrifuge. The centrifuged sweetwater was uncharacteristically
hazy and an unusually large thick layer of fatty acids, fatty acid soaps, and glycerides
accumulated in downstream processing tanks. The centrifuged sweetwater was concentrated
in a quadruple effect evaporator then, upon distillation, gave an unusually large
amount of residue, which corresponded to the lower amount recovered by the centrifuge,
leading to an additional loss of valuable glycerine. Distillation reboilers required
much more frequent clean-outs. Finally, it was discovered the fat accumulated and
fouled finished produce bleaching beds. It was believed that minerals from the city
water used in the earlier presplitting step caused these problems.
Example 2
Presplitting Performance Using Glycerine Evaporator Condensate Water
[0016] Glycerine evaporator condensate water was compared with fresh (city) water in laboratory
presplitting tests. LIPOLASE™ 100T (0.1467g) was rehydrated in 100 ml of city water
or cooled evaporator condensate water at room temperature. These stock solutions (0.3
ml) were each added to 10g of tallow with stirring at 60°C to observe the effect of
water on presplitting performance. The results, shown in Figure 2 (closed symbols),
indicate that evaporator condensate water has a detrimental effect on presplitting
performance. It was concluded that the condensate water could not be directly substituted
for city water in the process of example 1.
Example 3
Neutralization of Glycerine Evaporator Condensate Water
[0017] The pH of condensate water is about 3.5 - 4.5 by virtue of many C1 - C12 acids that
tend to accumulate in the evaporator condensate during sweetwater evaporation. These
may be readily neutralized by using, for example, caustic soda, calcium carbonate,
lime, or slake lime. The amount of these bases required to neutralize the short chain
acids is readily determined from an acid value measurement on the water. This was
tested using a cooled evaporator condensate sample (AV = 0.28) and adding calcium
carbonate at various levels up to 250 ppm which is the amount required for complete
neutralization. The partially and completely neutralized evaporator condensate was
used to rehydrate the LIPOLASE™ 100T as in example 2. The results also shown in Figure
2 (triangular symbols) demonstrate that normal presplitting performance can be achieve
by completely neutralizing the short-chain acids.
Example 4
DM Tallow Presplitting Using Glycerine Evaporator Condensate Water
[0018] An alternative approach to example 1 was attempted in which substantially all the
water of hydrolysis was supplied using uncooled and unneutralized evaporator condensate
and a minor amount of city water was used to prepare a concentrated lipase slurry
added during the presplitting reaction. Thus, a total of 29 million pounds of DM tallow
(AV = 8) was presplit to an average acid value of 48.4 by feeding DM tallow (37,900
lb/hr) to a continuous presplitting reactor (2.6 million pounds working volume) which
was agitated with a 10 hp blending agitator. LIPOLASE™ 100T was added at an enzyme/fat
feed ratio of 79.2 ppm by first making a slurry in city water (6-7 lb LIPOLASE™ 100T/4
gallons city water). The remaining major amount of hydrolysis water was added using
hot untreated sweetwater evaporator condensate at a water/fat feed ratio of 2.52%.
1. A continuous process for the production of carboxylic acids and glycerine from a glyceride
comprising the steps of: (a) forming a presplitting mixture by separately adding said
glyceride, an effective lipase in an amount sufficient to produce partial splitting
of said glyceride, and water wherein said water is recycled from step (c); (b) mixing
said partially split glyceride in a pressure splitter with water under conditions
of temperature and pressure effective to substantially complete the splitting of the
glyceride into component carboxylic acids and an aqueous glycerine solution, (c) separating
the water from the aqueous glycerine solution by evaporation and subsequent condensation;
(d) recycling said water to step (a).
2. The process of claim 1 wherein said partially split glycerides have an acid value
of at least 40.
3. The process of claim 1 wherein said temperature in said pressure splitter is in the
range of 200 to 300°C.
4. The process of claim 1 wherein said temperature in said pressure splitter is in the
range of 240 to 280°C.
5. The process of claim 1 wherein said pressure in said pressure splitter is in the range
of 3.10 to 6.55 MPa (450 to 950 psi).
6. The process of claim 1 wherein said glyceride is selected from the group consisting
of tallow, lard, coconut oil, canola oil, palm oil, and mixtures thereof.
7. The process of claim 1 wherein step A is conducted at a temperature less than 70°C.
8. The process of claim 1 wherein said lipase is selected from the group consisting of
a lipase from Burkholderia cepacia, ATCC 21,808, Mucor miehei, Caridida cylindracea,
Rhizopus arrhizus, or Humicola lanuginosa.
9. The process of claim 8 wherein said lipase is the lipase from Burkholderia cepacia,
ATCC 21,808 and the lipase from Humicola lanuginosa.
10. The process of claim 9 wherein said lipase is the lipase from Burkholderia cepacia,
ATCC 21,808.
11. The process of claim 9 wherein said lipase is the lipase from Humicola lanuginosa.
1. Kontinuierliches Verfahren zur Herstellung von Carbonsäuren und Glycerin aus einem
Glycerid mit den Schritten: (a) Herstellung einer Vorspaltungsmischung durch separate
Zugabe des Glycerids, einer wirksamen Lipase in einer zur Herbeiführung einer teilweisen
Spaltung des Glycerids ausreichenden Menge und aus Schritt (c) zurückgeführten Wassers;
(b) Mischen des teilweise gespaltenen Glycerids in einem Druckspalter mit Wasser unter
Temperatur- und Druckbedingungen, unter denen das Glycerid weitgehend vollständig
in seine Carbonsäurekomponenten und eine wäßrige Glycerinlösung gespalten wird, (c)
Abtrennen des Wassers von der wäßrigen Glycerinlösung durch Verdampfen und anschließendes
Kondensieren und (d) Zurückführen des Wassers in den Schritt (a).
2. Verfahren nach Anspruch 1, bei dem die teilweise gespaltenen Glyceride eine Säurezahl
von mindestens 40 aufweisen.
3. Verfahren nach Anspruch 1, bei dem die Temperatur im Druckspalter im Bereich von 200
bis 300°C liegt.
4. Verfahren nach Anspruch 1, bei dem die Temperatur im Druckspalter im Bereich von 240
bis 280°C liegt.
5. Verfahren nach Anspruch 1, bei dem der Druck im Druckspalter im Bereich von 3,10 bis
6,55 MPa (450 bis 950 psi) liegt.
6. Verfahren nach Anspruch 1, bei dem man das Glycerid aus der Gruppe bestehend aus Talg,
Schmalz, Kokosnußöl, Canolaöl, Palmöl und Gemischen davon auswählt.
7. Verfahren nach Anspruch 1, bei dem man Schritt A bei einer Temperatur von weniger
als 70°C durchführt.
8. Verfahren nach Anspruch 1, bei dem man die Lipase aus der Gruppe bestehend aus einer
Lipase aus Burkholderia cepacia, ATCC 21.808, Mucor miehei, Candida cylindracea, Rhizopus
arrhizus oder Humicola lanuginosa auswält.
9. Verfahren nach Anspruch 8, bei dem es sich bei der Lipase um die Lipase aus Burkholderia
cepacia, ATCC 21.808, und die Lipase aus Humicola lanuginosa handelt.
10. Verfahren nach Anspruch 9, bei dem es sich bei der Lipase um die Lipase aus Burkholderia
cepacia, ATCC 21.808, handelt.
11. Verfahren nach Anspruch 9, bei dem es sich bei der Lipase um die Lipase aus Humicola
lanuginosa handelt.
1. Procédé continu pour la production d'acides carboxyliques et de glycérine à partir
d'un glycéride comprenant les étapes de :
a) formation d'un mélange avant décomposition par fractionnement, par addition séparée
du glycéride, d'une lipase efficace en une quantité suffisante pour produire une décomposition
par fractionnement partielle du glycéride, et de l'eau, l'eau étant recyclée de l'étape
c) ;
b) mélange du glycéride en partie décomposé dans une colonne de fractionnement en
présence d'eau dans des conditions de température et de pression permettant de compléter
pratiquement la décomposition du glycéride en ses acides carboxyliques constitutifs
et en une solution aqueuse de glycérine ;
c) séparation de l'eau de la solution aqueuse de glycérine par évaporation puis condensation
;
d) recyclage de l'eau dans l'étape a).
2. Procédé selon la revendication 1,
caractérisé en ce que
les glycérides en partie fractionnés ont un indice d'acide d'au moins 40.
3. Procédé selon la revendication 1,
caractérisé en ce que
la température dans la colonne de fractionnement est dans la plage de 200 à 300°C.
4. Procédé selon la revendication 1,
caractérisé en ce que
la température dans la colonne de fractionnement est dans la plage de 240 à 280°C.
5. Procédé selon la revendication 1,
caractérisé en ce que
la pression dans la colonne de fractionnement est dans la plage de 3,10 à 6,55 Mpa
(450 à 950 psi).
6. Procédé selon la revendication 1,
caractérisé en ce que
le glycéride est choisi dans le groupe comprenant le suif, le saindoux, l'huile de
coco, l'huile de colza, l'huile de palme et leurs mélanges.
7. Procédé selon la revendication 1,
caractérisé en ce que
l'étape A est mise en oeuvre à une température inférieure à 70°C.
8. Procédé selon la revendication 1,
caractérisé en ce que
la lipase est choisie dans le groupe comprenant les lipases suivantes : une lipase
de Burkholderia cepacia, ATCC 21.808, Mucor miehei, Candida cylindracea, Rhizopus
arrhizus ou Humicola lanuginosa.
9. Procédé selon la revendication 8,
caractérisé en ce que
la lipase est la lipase de Burkholderia cepacia, ATCC 21.808, et la lipase de Humicola
lanuginosa.
10. Procédé selon la revendication 9,
caractérisé en ce que
la lipase est la lipase de Burkholderia cepacia, ATCC 21.808.
11. Procédé selon la revendication 9,
caractérisé en ce que
la lipase est la lipase de Humicola lanuginosa.

